Abstract: A switch mechanism comprising a housing in which a switch is mounted, the switch being actuable to switch between first and second conditions. A cam is mounted within the housing to rotate about a predetermined cam axis, the cam defining a cam surface against which a cam follower bears such that rotation of the cam causes displacement of the cam follower to activate the switch. An actuator shaft which may be connected to a safety rope is mounted to be axially displaceable within the housing, the actuator shaft being mechanically coupled to the cam such that axial displacement of the shaft causes the cam to rotate about its axis. The actuator shaft is positionable in an intermediate axial position in which the cam is rotatable to a predetermined rotational position such that the cam follower causes the switch to assume the first condition.